In recent years, the number of beverage dispensing machines in use has increased, found largely in cafeteria-style food service with large water consumption, such as in restaurants, hotels, bars, community centers, and canteens.
These sorts of water dispensers (henceforward the term will be used in its broadest sense of “beverage dispensing machine”, not limited only to water) have construction and operating characteristics that have become standardized, which will not be described in the present specifications.
For these purposes, suffice it to say that all types of dispensers require a connection to the water lines and, in the more advanced versions, require a chiller to chill the beverage dispensed and allow the user to select the desired water temperature.
At the same time, any type of water dispenser must also include a specific filter designed to ensure the highest quality of the water, eliminating impurities, lime and other undesirable substances from the water.
The most commonly used types of filters are essentially:                mechanical filters, with a washable mesh screen or similar features, which capture the deposited impurities;        filters in a composite structure in active carbons, able to capture impurities of 0.5 micron and larger; sometimes such filters are combined with a UV bactericide;        filters with ultra-filtering membrane, with holes of around one thousandth of a micron;        reverse osmosis filters that also capture dissolved mineral salts, modifying the chemical and physical composition of the water.        
Any type of filter must be submitted to ordinary maintenance which includes complete replacement after a certain time interval or after reaching a certain amount of dispensed water. Generally, it is recommended the replacement after 10,000/11,000 liters dispensed for standard filters (after 2,000/3,000 for smaller sizes); over this threshold, the exhausted filter ceases to work properly and could even release substances that could potentially contaminate the piping and the beverages dispensed to the user.
Therefore, it is essential not only to replace this filter, but also submit the water dispenser to a careful sanitization, which must be done periodically (generally every 6 or 12 months, depending on where the dispenser is installed and how frequently it is used) or before installing a new filter.
Sanitizing is done using acid solutions which can also remove lime deposits and bacteria biofilms that build up in time; the most commonly used solutions (although natural products can also be used) are comprised of one or more of the following chemical substances: hydrogen peroxide, active chlorine in a number of compounds, phosphoric acid, ozone, active oxygen, quaternary ammonium salts, and other substances. All these sanitizing products must be effective but must also be easily rinsed away to prevent disinfectant residue from being left on the dispenser when it is dispensing drinking water again.
In certain cases, users can handle the sanitizing process on their own by purchasing a special kit that includes a sanitizing product cartridge which is installed temporarily in place of the filter. However, in view of the importance of the procedure, sanitizing frequently requires a specialized technical service, which usually carries out the cleaning and sterilization of all the components in contact with the water by using a pump that injects the sanitizing solution into the water (similar to the method used to remove lime deposits from hot water heaters) or other methods. Finally, the sanitizing procedure requires care and additional expenses, whether maintenance is performed directly by the user or in a technical service call.
The purpose of this invention is to circumvent at least a part of the difficulties described above by developing a filter with a sanitizing device built in. This and other purposes, which will become clear below, are achieved in a sanitizing device incorporated into the usual water dispenser filter.
Additional features of the present invention will be better identified in the following description of a preferred embodiment, provided by way of a non-limiting example, in which: